With development of network technologies, there is a growing trend in the industry that an existing network function implemented by a dedicated network device is transferred to multiple general-purpose computer devices and implemented by software. Each computer device is configured to execute one type of service, or multiple service instances may be deployed on one computer, and each service instance is used to execute one type of service. Therefore, on the one hand, hardware costs may be reduced; on the other hand, network deployment flexibility may be enhanced, so that an operator more easily implements, based on an existing device, a service upgrade and performs secondary development of a network service.
In an existing packet forwarding method, after receiving a packet, a router searches a routing table according to a destination Internet Protocol (Internet Protocol, hereinafter referred to as IP) address of the packet, and obtains an IP address of a next-hop device; then, forwards the packet to the next-hop device. Therefore, service packet forwarding among multiple service instances cannot be implemented by using the existing packet forwarding method.